Other Government Links Searched via RegsKnowledge:

Example Content from MEDITEXT for Methidathion:

Please note: this is an extract of information from a larger document. Full document and details are available by subscription.

ACUTE EXPOSURE INFORMATION

USES: Methidathion is an organophosphate insecticide. It is not registered as a pesticide in the USA.

TOXICOLOGY: Organophosphates competitively inhibit pseudocholinesterase and acetylcholinesterase, preventing hydrolysis and inactivation of acetylcholine. Acetylcholine accumulates at nerve junctions, causing malfunction of the sympathetic, parasympathetic, and peripheral nervous systems and some of the CNS. Clinical signs of cholinergic excess can develop.

EPIDEMIOLOGY: Exposure to organophosphates is common, but serious toxicity is unusual in the US. Common source of severe poisoning in developing countries.

The following are symptoms from organophosphates in general, which are due to the anticholinesterase activity of this class of compounds. All of these effects may not be documented for methidathion, but could potentially occur in individual cases.

DELAYED EFFECTS: Intermediate syndrome is characterized by paralysis of respiratory, cranial motor, neck flexor, and proximal limb muscles 1 to 4 days after apparent recovery from cholinergic toxicity, and prior to the development of delayed peripheral neuropathy. Manifestations can include the inability to lift the neck or sit up, ophthalmoparesis, slow eye movements, facial weakness, difficulty swallowing, limb weakness (primarily proximal), areflexia, and respiratory paralysis. Recovery begins 5 to 15 days after onset. Distal sensory-motor polyneuropathy may rarely develop 6 to 21 days following exposure to some organophosphate compounds, however, it has not yet been reported in humans after exposure to methidathion. Characterized by burning or tingling followed by weakness beginning in the legs which then spreads proximally. In severe cases, it may result in spasticity or flaccidity. Recovery requires months and may not be complete.

CHILDREN: May have different predominant signs and symptoms than adults (more likely CNS depression, stupor, coma, flaccidity, dyspnea, and seizures). Children may also have fewer muscarinic and nicotinic signs of intoxication (ie, secretions, bradycardia, fasciculations and miosis) as compared to adults.